'84 1200 engine for a '82 GW

[canuckxxxx]

slabghost » Thu Jul 23, 2015 11:50 pm[/url]":1fxqo1wn]

canuckxxxx » Thu Jul 23, 2015 9:59 pm[/url]":1fxqo1wn]
The trouble is that the 1100 cams are designed for 5 BTDC for intake opening, 5 ATDC for exhaust closing. When I advance the intake to 10 BTDC the exhaust will close at TDC. Should give increase in torque though but might affect gas mileage.

I filled up this AM after I got it all together with 5 BTDC so I think I will ride like this so I can get a gas mileage check. Then I can see if it gets way worse at 10 BTDC.

Actually if intake opens @ 5btdc Exhaust opens @ 45 bbdc . So 10 btdc on intake will have exhaust opening @ 50 bbdc and closing @tdc.
Your bike your choice.

 

[canuckxxxx]

canuckxxxx » Mon Jul 27, 2015 2:41 pm[/url]":2yvxernt]

slabghost » Thu Jul 23, 2015 11:50 pm[/url]":2yvxernt]

canuckxxxx » Thu Jul 23, 2015 9:59 pm[/url]":2yvxernt]
The trouble is that the 1100 cams are designed for 5 BTDC for intake opening, 5 ATDC for exhaust closing. When I advance the intake to 10 BTDC the exhaust will close at TDC. Should give increase in torque though but might affect gas mileage.

I filled up this AM after I got it all together with 5 BTDC so I think I will ride like this so I can get a gas mileage check. Then I can see if it gets way worse at 10 BTDC.

Actually if intake opens @ 5btdc Exhaust opens @ 45 bbdc . So 10 btdc on intake will have exhaust opening @ 50 bbdc and closing @tdc.
Your bike your choice.

OK, I got around to putting new offset keys in that I thought would give 10 BTDC but when I measured with degree wheel it was 11 BTDC on both sides...close enough. Making keys with a file and vice is not an exact science. Anyway if some advance is good then more must be better, right! :smilie_happy:

Just went for a short test ride because weather is crappy here. Nice increase in torque. Pulls smoothly and strongly from 2500 rpm in top gear.

Should be able to go for a longer ride tomorrow and I will check gas mileage. I went for about 100 mile ride on Saturday with 5 BTDC setup and got 35 mpg so will see how new setup compares.

Brian

 

[dan filipi]

Very interesting thread.

Valve timing tweaks are pretty new territory so it's fun to follow.

 

[canuckxxxx]

I agree totally Dan...very interesting. I never gave it a second thought until I ran into the problem of putting 1100 heads on the 1200 and finding the timing was off. In trying to correct that I advanced the timing a whole bunch and found a big increase in torque and compression. Quite by accident, really.

Like so many things on a GW, like single carbs, the layout makes it easier than with most engines to do this stuff. It's a real shame that the aftermarket didn't embrace these engines. There is so much speed potential IMO.

Brian

 

[ekvh]

Cool, Brian. Looking forward to more posts. This is with a Weber? Mine must be close to that with 77 carbs, cams. I have two spots I can't get right. One, if I go from second or third and downshift to a lower gear at above 4k it slams the slides up too quickly and sputters. It also just flutters or has a little miss at 3500-4500. I am concerned with the 35-4500 rpm as I am unsure if it's lean or rich. If it's lean, I'm worried it could hear up on extended speeds on the interstate. I have tried everything except shaping the needle. I am afraid to try that, even though I have spares. I have been bumping my jets in increments of ten, maybe I need to try five? I have 62 primary and 120 main right now. I tried air jets first. Just can't seem to find perfect. Nothing new to me there.

 

[canuckxxxx]

ekvh » Mon Jul 27, 2015 8:09 pm[/url]":1wog8f5j]
Cool, Brian. Looking forward to more posts. This is with a Weber? Mine must be close to that with 77 carbs, cams. I have two spots I can't get right. One, if I go from second or third and downshift to a lower gear at above 4k it slams the slides up too quickly and sputters. It also just flutters or has a little miss at 3500-4500. I am concerned with the 35-4500 rpm as I am unsure if it's lean or rich. If it's lean, I'm worried it could hear up on extended speeds on the interstate. I have tried everything except shaping the needle. I am afraid to try that, even though I have spares. I have been bumping my jets in increments of ten, maybe I need to try five? I have 62 primary and 120 main right now. I tried air jets first. Just can't seem to find perfect. Nothing new to me there.

Yes, this is all with the single Weber. You are doing some very innovative things with your carbs. I had the OE carbs off and on a few times when I first got the bike but they are way too complicated for me.

Brian

 

[ekvh]

I timed myself today. From on the lift, to carbs on the bench: seven minutes. Too much practice.

 

[canuckxxxx]

How in the heck .... :shock:

 

[dan filipi]

Man that is fast.
Typically would take me 20-30 minutes.

 

[slabghost]

Can't wait for this ride report.

 

[canuckxxxx]

Well I got a ride in today. :moped: Went the same route as Monday when the valves were timed at 5 BTDC (now they are at 11 BTDC). I would say that it has a more torque at a lower RPM but not much use in reving it past about 6k RPM...torque drops off. Whereas with 5 BTDC it had more of a top end surge right up to 8k RPM. Not really massive torque but plenty to cruise at 65 - 70 mph very smoothly and comfortably. Cruised at 80 mph for a bit and it does that effortlessly...just more wind. Had the throttle lock on sometimes and when I hit a hill the speed might go down from 65 to 62 - 63. I haven't filled it up yet so can't report on mileage...will do that tomorrow. But the fuel level didn't seem to drop any faster than the previous ride so I expect similar mileage. Also I didn't do a compression test but will do that too.

Quiet secondary country roads north of Calgary, farms, nice sunny day...very pleasant. :music2: The taller 5th gear of the 1200 makes for very relaxed highway cruising. :lazy: There is a sweet spot when I crouch down where there is no wind noise at all and all you hear is the low hum of the engine. :yes: I was trying to get that without crouching by raising the wind screen more and more and by leaning forward so my face is only about a foot away from the WS and I'm just looking over the top of it. I'm not quite there yet but close. Does a full dress 1200 gives you that quiet bubble of still air at highway speeds? If so then that is what I want. The naked GW is cool but today I got a vision of why people like the full dressers for traveling. For awhile I forgot about all the numbers (compression, valve timing, etc) and just enjoyed a classic GW experience. :music2:

Brian

 

[slabghost]

Did you use the 1100 or 1200 ignition? Advance on the 1200 I think is all done by computer. 1100 has mechanical and vacuum advance which may be why you have no top end.

 

[Denver]

1200 with Tulsa windscreen is quiet, :good: but 1500's with one sounds almost like an electric motor, have to listen to hear it run. :yes: But BOTH faired bikes have not left garage in at least a month, & 87 has not left the garage since changed tires, did brakes, fluids & put on new fuel pump. Thats been over two months, but things will change when weather does, :hihihi: both standards will be put over in the far corner, for the year. :crying:

 

[canuckxxxx]

slabghost » Thu Jul 30, 2015 3:42 am[/url]":4tp80x99]
Did you use the 1100 or 1200 ignition? Advance on the 1200 I think is all done by computer. 1100 has mechanical and vacuum advance which may be why you have no top end.

I swapped the 1100 ignition over to the 1200.

 

[slabghost]

Might want to use a timing light to see where it is.

 

[canuckxxxx]

Denver » Thu Jul 30, 2015 4:08 am[/url]":12d7u2q7]
1200 with Tulsa windscreen is quiet, :good: but 1500's with one sounds almost like an electric motor, have to listen to hear it run. :yes: But BOTH faired bikes have not left garage in at least a month, & 87 has not left the garage since changed tires, did brakes, fluids & put on new fuel pump. Thats been over two months, but things will change when weather does, :hihihi: both standards will be put over in the far corner, for the year. :crying:

Thanks for the info, Denver. I can only imagine what a 1500 would be like. :lust: I assume a Tulsa WS is taller than OE and you are looking through it, not over...is that right. I always wear ear plugs to reduce wind noise but maybe you wouldn't need to with the Tulsa WS. With the regular height WS do you get buffeting?


Brian

 

[canuckxxxx]

slabghost » Thu Jul 30, 2015 4:28 am[/url]":mxxa1hnr]
Might want to use a timing light to see where it is.

Well there is an idea...never thought of checking ignition timing. Will do.

Thanks Slab
Brian

 

[slabghost]

:hi: You're welcome. From the sound of it I expect the timing is retarded from where it should be.

 

[canuckxxxx]

slabghost » Thu Jul 30, 2015 4:59 am[/url]":1vs9ii4a]
:hi: You're welcome. From the sound of it I expect the timing is retarded from where it should be.

Well that could make a big difference. I checked timing a couple of years ago when I first got the bike and I remember I had to glue a piece of lexan over the fly wheel inspection hole, with gasket maker, so I could see the flywheel marks while the engine was running. So it might not be until tomorrow that I can check timing.

Brian

 

[ekvh]

Not sure, but I think the 1200 uses a combination of which gear you are in and vacuum to adjust timing via a black box. I think it had a few more degrees advance available this way.